This application is related to Japanese application No. 2001-278506 filed on Sep. 13, 2001, whose priority is claimed under 35 USC xc2xa7119, the disclosure of which is incorporated by reference in its entirety.
1. Field of the Invention
The present invention relates to a display device, and more particularly to a display device for displaying an optional image, wherein a plurality of elongated gas discharge tubes are arranged in parallel.
2. Description of the Related Art
The present inventors filed Japanese Patent Application NO. 2001-276941 relating to a display device having a plurality of elongated gas discharge tubes arranged in parallel for displaying an optional image.
FIG. 6 shows this display device. In the figure, numeral 31 denotes a front side substrate, 32 a back side substrate, 1 a gas discharge tube, 2 a display electrode pair and 3 a data electrode.
A phosphor (fluorescent) layer (not shown) is provided in the gas discharge tube 1 that is an elongated tube. A discharge gas is filled in this gas discharge tube 1. The data electrode 3 is formed on the back side substrate 32 so as to be arranged along the longitudinal direction of the gas discharge tube 1. The display electrode pair 2 is formed on the front side substrate 31 so as to be arranged in the direction perpendicular to the data electrode 3.
When this display device is seen from the top, the intersectional point of the data electrode 3 and the display electrode pair 2 becomes a unit light-emitting area. With respect to display, one of the display electrode pair 2 is used as a scanning electrode for generating a selective discharge between the scanning electrode 2 and the data electrode 3 to thereby select a light-emitting area. Thereafter, a display discharge is generated with the display electrode pair 2 by utilizing wall charges formed by the selective discharge on the inner surface of the tube at the selected light-emitting area, whereby the phosphor layer emits light to execute the display. The selective discharge is a counter discharge generated in the gas discharge tube 1 between the scanning electrode and the data electrode 3 that are opposite to each other in a vertical direction. The display discharge is a surface discharge generated in the gas discharge tube 1 at the display electrode pairs arranged parallel to one another on a plane.
In the display device having a great number of such gas discharge tubes arranged therein, the display electrode pair 2 has an electrode structure shown in FIG. 7 or shown in FIG. 8.
The electrode structure shown in FIG. 7 has the display electrode pair 2 formed on the inner surface of the front side substrate 31 as shown in the above-mentioned FIG. 6. The display electrode pair 2 is arranged so as to be in contact with the outer wall surface of the gas discharge tube 1 upon assembling.
The electrode structure shown in FIG. 8 has the display electrode pair 2 that has already been formed on the outer surface of the gas discharge tube 1 by a printing method or vapor-deposition method. Formed on the front side substrate 31 is an electrode 2a for an electric power supply. This electrode 2a for the electric power supply is arranged so as to be in contact with the display electrode pair 2 of the gas discharge tube 1 upon assembling.
However, the contact area between the display electrode 2 and the gas discharge tube 1 is small in the display device having the electrode structure shown in FIG. 7, which leads to an excessive small effective electrode area. Therefore, a discharge D between the display electrodes 2 is small, to thereby entail a problem of dark display luminance.
The display device having the electrode structure shown in FIG. 8 requires an alignment between the display electrode 2 formed on the gas discharge tube 1 and the electrode 2a for the electric power supply.
The present invention is accomplished in view of the above circumstances, and aims to improve a display luminance of a display device by enlarging a contact area between a display electrode and a gas discharge tube without forming an electrode on the gas discharge tube.
The present invention provides a display device comprising: an elongated display tube to be filled with a discharge gas and provided with a phosphor layer therein; a supporter in contact with the display tube for supporting the display tube; and a plurality of electrodes arranged on a surface of the supporter facing the display tube, for externally applying a voltage to the display tube to generate discharge in the display tube so as to perform a display, wherein the supporter has a shape fitting the display tube whereby the electrode is in contact with the display tube along the surface shape of the display tube.
According to the present invention, the supporter has a shape along the display tube, by which the electrode is in contact with the display tube along the surface shape of the display tube. Therefore, the contact area between the electrode and the display tube becomes a curved surface, whereby the electrode and the display tube sufficiently contact with each other. This can assure a sufficient effective area of a discharge electrode, thereby improving the display luminance of the display device.